Kinson



(No Model.)

0. W. & L. B. ATKINSON.

CUTTER 0R DRILL FOR GOAL. No. 482,033. Patented Sept-6, 1892.

\\/l mu j j o I @Imw mikesscs: int 6711375.

" "darr CLAUDE WILLIAM ATKINSON.

UNITED STATES "PATENT FFICE- I CUTTER OR DRILL FOR COAL.

SPECIFICATION formingpart of Letters Patent No. 482,033, dated September 6, 1892. Application iiledAugnst 18,1891. Serial No.403,025 (No model.)

- Tea/ll whom it may min. 7

Be it known that we,- CLAUDE WILLIAM A'r- KINSON and LLEWELYN BIRCHALL ATKINSON,

.civil engineers, subjects of the Queen of Great Britain and Ireland, residing at London, England, have invented Improvements in Cutters or Drills for Goal, of which the following is a specification.

This invention relates to improvements in,

cutters or drills applicable to coal or other materials either in the form of a cutter-bar in which the cutters are disposed'along its length or in the form of a disk, the cutters being arranged around. the periphery of the disk for the purpose of cutting a deep slot in the face of the material, or in cutter-bars used for the purpose of forming circular holes in the same.

- .Tnasuch cutters or drills as have beenherea tofore made the material forming the cuttingedge has been supported in the bar, disk, or mandrel in one piece-that is to say, a considerable portion of the cutting-tool has to be embedded into the bar which holds it, thereby ter understood, we will now describe the same in relation to the drawings hereunto annexed, reference being had to the letters marked thereon, the bar of the taper form, as before referred to, being used for the purpose of description, so as toshow one method of carry-' ing out our invention.

Figure 1 is a side view of acutter-bar with tool-holders and tools attached. Fig. 2 is a section of the bar, showing a tool helder' partly in section and the tool in section "removed therefrom. Fig. 3 is a View of the tool-holder removed from the bar. Figs. 4, 5, and 6 are views of a modified tool.

Consequently the largestholder.

In place of the steel cutters formerly used we substitute a cutter-holder A in the form of a projecting shank, which is mounted upon the cutter-bar B, preferably by screwing it into the same; but it may be attached by forming the shank-taper so as to be frictionallyheld in the bar in av similar manner to vantage, however, of screwing these .holders A into the bar 13 is that a great reduction is AND LLEWELYN B. ATKINSON. on LONDON,

,ENGLAND.

. the cutters before described. One great adefiected in the amount of material of the bar I that has to be removed for the purpose of attaching the cutter. At the outer end of this shank or liolder A the hole 0 is arranged, which in the case of a cutter-bar for cutting a deep slot in the face of the" coal or other unaterial, will be at right angles or about right angles to the axes of the holder and bar.""Tl'iis hole 0 may be round, square, polygonal, parallel, (uniformly cylindrical throughout) or taper; but we preferfto make itround and. taper in order to facilitate the attachment and detachment of the cutter therewith.

The cutter I) may be made-of varying shapes to suit the material to be out, and is mounted in the'hole C at the end of the holder A in such a way that the pressure produced by cutting tends to force it tighter into its The cutters, as shown in Figs. land 2, are of a circular cupped form, having a taper shank d, which engages with the taper hole Gin the holder A. The tool is so shaped, or the hole is so inclined, if necessary, as toallow the cutting-edge to project radially "beyond the shank A. The great ad vantage oil this circular-cupped tool is that as one part ofthe circumferential cutting-edge becomes: worn the cutter, can be withdrawn from its holder A and turned, so as to present a fresh cutting-edgeto the materialtmbe out until the whole circmnferenoe has been worn away. In Figs. 4, 5, and '6 we show a form of cutter having two cutting-edges only, the cutter being of the diamond shape and having a taper shank d to attach it to the holder. The front face of each half of the cutteris ground off .at an angle, so that the cutting-edge: e leads a trifle in advance of 'theedge e. W hen the one side of the cutter has become worn,

' the cutter is knocked from its holder and the cutting-edges turned end for-end.

A very high efliciency of cutting efifect is obtained with the diamond-shaped cutter if the holder A is so adjusted upon the bar that the point f of the cutter, Fig, 6, revolves in a.-

ditferent plane ofv revolution to the point F.

The effect of this is that the poiutf cuts a groove in the coal and the edge between f and 1 breaks oif thecoal between one rroove and another, the result being that the actual amount of coal that is cut is very'smalhthe;

majority being broken olfand the power requiredkfor driving the machine isconsequently much reduced. It is obvious that this method of" mounting the cutters is considerably cheaper than those used heretofore, as the amount of cutting-edge material used in the bar is reduced very considerably-say to about one-twentieth-of that -used where the cutters are mounted in the bar direct-and, further, as before described, when the cuttingedge has become blunt-it can be turned about former, as being considerably cheaper.

As shown in Fig. 1 it will be noticed that the tool-holders A are arranged upon the barin double spiral form-tl1atis tosay, one way on a left-hand spiral of large pitch, say once the length of the bar and about four spirals,

and the other a number of right-hand spirals of short pitch. Theholders are placed on the intersection of a left-handed spiral long pitch and right-handed intersecting short pitch, as shown in Fig. 1. One dotted line without holders on it represents thelong-pitch line at the back of the bar.

The cutters are arranged on the shortpitched right-handed spiral to give a feed backward toward the flanged end of the bar to the dbris of coal from the cutter. If the cutters were further arranged on the longitudinal axiallines,-all the cutters on such a line would engage with the coalstratum simultaneously, and when an especiallyhard layer of shale or conglomerate were struck the concentrated resistance of the obstructions upon the whole line of cutters would tend to stop the machine or to give a heavy jar thereto. By arranging the cutters on the intersections of a left-handed spiral pitch of equal'length of the bar the cutters only ongage successively upon the working face of the cut and the resistance to cutting is distributed over the entire rotation of the bar.

It is obvious that our invention is equally applicable to tools for purposes of face-cut- :ting,such as that required for drilling a hole of four inches or any other dimension, in which case we arrange one or more of the cutters,as before described, on the cutter-bar, the end of the bar being supported in a small hole previouslymade. The cutters and their holders are so-arrang'ed in respect to the bar that they cut out an annular groove or grooves about the axis of rotation. Having now particularly described and ascertained the nature of our invention and in what manner the same is to be performedfi we declare that what we claim is- 1. In a cutter bar or drill for coal or other minerals, the combination, with a cylindrical bar, of a series of tool-holders arranged at and fitted-into'holes in the intersections of right and left handed-spirals ofdifferentpitch, one

with pitch the length of the bar and the other intersecting spiral with a pitch of about onetenth the length of the bar, substantially-as set forth.

2. In a cutter bar or drill for coal or other mineral, a diamond-shapedeutting-tool ,witha taper shank detachablyattached-to a holder 5 A, incombination witha revolving bar supporting the said holders, the cutter being so disposedin the holder andte the bar that the front and-back corners of thecutting-edge rotate in different-planes ofrevolution, substantially-as and for the purpose-specified:

,In testimony whereof we have signed-our names to this specification in the presence of two subscribing witnesses.

CLAUDE WILLIAM ATKI-Nson; v

LLEWEEYN'B. ATKINSON. Witnesses:

Tom; M. T'IJLEY,

CHARLES F. Aenowsm'rm 

